This invention relates to an improved system for storing items while they are being sterilized, while they are being stored awaiting use, while they are in the process of being used, and after they have been used and are awaiting resterilization. The system is particularly useful in connection with the sterilization and storage of medical items, such as surgical instruments.
The most commonly used method for sterilizing surgical instruments and other medical items is to place them in towels which are enclosed in a sheet and taped shut for placing in a sterilizing autoclave. Sterilizing steam applied to the interior of the autoclave penetrates the porous materials surrounding the items to be sterilized. Moisture is removed by a vacuum drying cycle within a vacuum autoclave. When pressure is then returned to normal by admitting room air, unsterile air and lint from the towels are drawn into the center of the package. When the package is removed from the autoclave and cooled, additional room air circulates into the package. Thus, the items are immediately contaminated to some extent. If the package is not used immediately and placed in storage for a period of time, it must be returned to the autoclave for resterilization. It is estimated that two-thirds of sterilization work load in many hospitals is for items that were not used within the shelf life of the pack. This of course is an expensive and inefficient procedure which adds to the skyrocketing costs of medical treatment. Thus, a need exists for a practical and reliable system for handling sterile items and for maintaining sterility.
The above-referenced patent applications and two earlier patent applications Ser. No. 710,521, filed Aug. 2, 1976, now abandoned, and Ser. No. 710,522, filed Aug. 2, 1976 which issued as U.S. Pat. No. 4,105,407 on Aug. 8, 1978 in the name of Roger S. Sanderson disclose containers in which the items to be sterilized are placed before the container is placed within the sterilizer. The container is initially sufficiently open to permit the sterilizing environment to circulate within the interior of the container and the container is then sealed at an appropriate stage to maintain sterility. Further, the container is constructed such that steam can escape or be withdrawn from the container when the pressure on the interior of the container exceeds the pressure on the exterior. Consequently, the container is essentially dry with a vacuum type autoclave wherein a vacuum is applied to the container at the end of the steaming cycle. Also, only a slight amount of moisture remains in the container with a gravity type autoclave for most sterilizing operations, and this moisture can be absorbed by a small quantity of dessicant.
While the systems disclosed in the above-referenced applications provide valuable contributions to the sterilization art, it has been found that with loads, involving a considerable mass, such as a large quantity of surgical instruments, steam must be circulated through the autoclave for a considerable period of time to heat the load to the necessary sterilizing temperature. Further, during this operation, a considerable amount of steam condenses on the cold metal. Although this condensate is eventually sterilized if it remains within the autoclave, it is desirable that the container in which the load is stored be as dry as possible. Accordingly, a need exists for insuring that condensate is removed before the container is sealed; and it is further desirable that the means for sealing the container will function in response to the sterilizing cycle regardless of the length of the steaming phase.